Remove AUDIOSERVER_MULTILIB assignment, this is 64-bit device.

Bug: 121208203
Test: treehugger
Change-Id: Ib9d5bac0cc64a1b97046d1c938b8b8affb6e5a1e
diff --git a/hikey64/BoardConfig.mk b/hikey64/BoardConfig.mk
index c690185..56f5111 100644
--- a/hikey64/BoardConfig.mk
+++ b/hikey64/BoardConfig.mk
@@ -1,7 +1,5 @@
 include device/linaro/hikey/hikey/BoardConfig.mk
 
-AUDIOSERVER_MULTILIB := 64
-
 TARGET_ARCH := arm64
 TARGET_ARCH_VARIANT := armv8-a
 TARGET_CPU_ABI := arm64-v8a